Carrier frame for movable contact and combination thereof with snap acting switch



Aug. 10, 1965 w. c. KARCH 3,2 CARRIER FRAME FOR MOVABLE CONTACT ANDCOMBINATION THEREOF WITH SNAP ACTING SWITCH Original Filed Sept. 29.1960 2 Sheets-Sheet l INVENTOR. Wa d l BY ATTORNEY 0, 1965 w. c. KARCH3,200,227

CARRIER FRAME FOR MOVABLE CONTACT AND COMBINATION THEREOF WITH SNAPACTING SWITCH Original Filed Sept. 29 1960 2 Sheets-Sheet 2 23 23a 25 /5F a? I r 32 I", HI I as 7 INVEN TOR.

M a KM, 3'76 43 4.4- 44 a5 /5 24- BY United States Patent 3,20%,227CARRIER FRAME FOR MGVABLE CONTACT AND (IQMBIINATIGN THEREOF WITH FaNAPAEITENG SWITtCH Waiter C. Karch, Milwaukee, Wis, assignor to Square DCompany, Park Ridge, R1,, a corporation of Michigan Original applicationSept. 29, 1960, Ser. No. 59,363, new Patent No. 3,017,471, dated Jan.16, 1962. Divided and this appiication Sept. 22, 1961, Ser. No. 139,9716 Claims. (Ci. 200-168) This is a division of application Serial No.59,363, filed September 29, 1960, now US. Patent No. 3,017,471, issuedJanuary 16, 1962.

This invention relates to electrical switches of the snapacting type inwhich a contact carrier is movable from on to off positions with a snapaction by a dead-center spring consequent upon initial movement of thecarrier toward the selected position, either by a suitable actuatingmeans or by a return spring.

As pointed out more fully in my copending application switches of thischaracter are sold in a highly competitive market and it is necessary,therefore, that the working parts thereof be capable of beingmanufactured and assembled with a minimum of manual labor. Further, itis equally important that the switch be small and compact in relation toits rated maximum voltage and current, yet strong enough to operateseveral million times with a snap action without breakage or damage tothe parts.

In the identified copending application, the claims are directed to themanner of fastening the movable bridging conductor element to itscarrier.

An additional important feature of the invention resides in the mannerin which the grooves for connecting the dead-center snap-acting springsto the carrier are arranged. The claims of the present application aredirected to this additional feature.

For the purposes of illustration, the invention herein is disclosed inconnection with a double-pole, double-throw snap-acting switch employinga movable carrier and two contact assemblies which can be installedreadily on the carrier and removed therefrom and replaced readily forservicing, yet which, when installed, are retained effectively in properposition for operation over long periods of use.

The manner in which the invention can be incorporated in other types ofswitches will be readily apparent from the illustrative example in whichreference is made to the drawings, wherein:

FIG. 1 is an isometric view of a switch embodying the principles of thepresent invention;

FIG. 2 is an exploded isometric view of the switch illustrated in FIG.1, showing the parts in the position for assembly;

FIG. 3 is an enlarged top plan view of the switch illustrated in FIG. 1with the cover removed, and with the upper stationary contacts andmovable contact assembly removed in the right-hand portion;

FIG. 4 is a front elevation of the structure illustrated in FIG. 3 withthe cover plate in place, part of the structure being shown in sectionfor clearness in illustration, as indicated by the lines 44 in FIG. 3;

FIG. 5 is an enlarged top plan view of the carrier frame of the presentinvention; and

FIGS. 6 and 7 are vertical sectional views taken on the lines 66 and7-7, respectively, of FIG. 5;

FIG. 8 is a fragmentary isometric view of the pushbutton and carrier,with the contact bridges and mounting springs, illustrated in FIG. 2,but with the carrier inverted;

FIG. 9 is an enlarged cross sectional view of the carrier and bridgingconductor taken on the line 99 in FIG. 8;

FIG. 10 is an enlarged top plan view of a bridging conductor; and

FIG. 11 is a longitudinal sectional view of the bridging conductor andis taken on line 11-11 of FIG. 10.

Referring to the drawings, the switch comprises a hollow body 1 normallyclosed by a suitable cover plate 2. The body is preferably made ofinsulating material and embedded in each end is a pair of metalconducting sleeves 3. A metal conductor 4 is fastened fixedly by asuitable screw 5 to each sleeve and on its under face carries astationary contact 6. The other end of each sleeve 3 carries a screw 7which is accessible for operation through the bottom of the body forclamping a wire to the sleeve 3 and thereby effecting an electricalconnection to the upper stationary contact a. Two stationary contacts 6are provided at each end of the body and are spaced laterally of thebody from each other. A pair of lower stationary contacts 9 is arrangedat each end of the body. Each pair is secured to the body by a suitableconducting sleeve 10 which, in turn, receives a screw 11 for connectinga wire thereto. Each lower stationary contact 9 of each pair is arrangedbeneath and in alignment with a corresponding upper contact 6 of thepair thereabove.

In operation of the switch, it is desirable to bridge the upper contacts6 of each pair by a bridging conductor in one position of the switch,and to bridge the lower contacts 9 by the same conductor in anotherposition of the switch. For this purpose, movable contact assemblies areprovided, one for each set of aligned upper and lower stationarycontacts.

Each assembly comprises a bridging conductor element 12 and upper andlower contacts 13 and 14 thereon, the contacts 13 being cooperable withthe contacts 6 and the contact 14 being cooperable with the contacts 9,of their associated set.

In order to move the assemblies to different contact making and breakingpositions, a carrier frame'15 is provided and is floatingly mounted inthe body. For supporting the carrier frame in the body for movement tocause the assemblies to make and break contact with respect to thedifferent stationary contacts, an actuator 16 is mounted in the body 1for movement upwardly and downwardly. The carrier frame 15 preferably isin the form of a frame and has a central opening 17. The actuator 16 hasportions in the form of depending legs 16a which extend through theopening 17 and through a pair of oppositely facing notches 18 in thecarrier frame 15 and are received in suitable guideways 19 in thebody 1. The clearance is provided between the legs 16a and the walls ofthe notches 18. The guideways guide the actuator in a'lineal pathupwardly and downwardly relative to the cover 2 The actuator 16 also hasa portion in the form of a push-button 26 having a reduced diameterportion and a shoulder 20a. The reduced diameter portion extends througha suitable opening 2a in the top cover 2 and is accessible for operationby hand or for connection to a suitable operating mechanism foroperating the switch. The shoulder 20a is engaged by the underside ofthe cover 2 and the button is held partially depressed thereby.

It is desirable that the carrier frame 15 be moved, with a snap action,downwardly upon depression of the button 20 and upwardly upon upward orreturn movement of the button 20. The actuator 16 is moved upwardly by areturn spring 21 when the button 211 is released. In order to provide asnap action for causing the frame to snap upwardly when the button isdepressed and snap downwardly when the button is returned, dead-centersprings are provided and interconnect the actuator and carrier.

For this mounting, the carrier frame is provided at each of its oppositeends with a pair of internal shoulders 23 and an internal cooperatingshoulder 23a. Correspondingly, the actuator 16 is provided at oppositesides with notches 24. Each notch 24 is adapted to receive one end of asnap-action, dead-center spring 25, of which the other end is bent, asindicated at 26, to be accommodated between the shoulder 23a andshoulders 23 on the carrier frame.

Thus, each spring is stressed resiliently in position between one set ofthe shoulders 23 and 23a and the base of the adjacent notch 24 and isheld so engaged by the forces imposed by its own stressed condition.Each spring 25 preferably has a loop portion 27 intermediate its ends toassist in the snap action by permitting the length of the springs 25 tobe reduced as they approach and pass dead center.

The normal location of the shoulders 23 and 23a and the notches 24, whenthe button is held in partially depressed position by the engagement ofthe cover with the shoulder 20a, is such that the springs beardownwardly on the carrier frame 15, the ends of the springs 25 in thenotches 24 being upwardly above the level of the shoulders 23 and 23a.This holds the carrier so that the lower contacts 14 of the bridge arepressed into firm contact with the lower contacts 9. When the button 2t?is fully depressed, the bases of the notches 24 are below the level ofthe shoulders 23 and 23a. Thus, when the button 20 is depresser, theends of the springs received in the notches 24 are moved to a positionbelow the level of the shoulders 23 and 23a and the springs exert theirsnap action force so as to lift the carrier frame 15 upwardly. Whenagain the button 26 is released and returned by the spring 21, the baseof the notches 24 move to a position above the level of the shoulders,whereupon the springs exert their snap action force to move the carrierframe 15 downwardly.

It is to be noted, as illustrated in FIGS. 6 and 7, that the shoulder23a slopes downwardly outwardly endwise of the frame from themid-portion of the frame and the shoulders 23 slope upwardly outwardlyendwise of the frame from the mid-portion. The upper edges of theshoulders 23 and the lower edge of the shoulder 23a preferably intersecta first reference plane parallel to the plane of the frame 15 so thatthe intersections define a single straight line. The shoulders 23terminate at their inner ends, in a direction which is parallel to saidfirst referenced plane and transversely of the length of the frame, inspaced relation to each other at opposite sides of a reference planewhich extends lengthwise of the frame along the longitudinal medium lineof the frame and which is at substantially a right angle to the firstreference plane. The shoulder 23a is aligned, in a direc tion normal tothe plane of the frame, with the space between the adjacent inner endsof the shoulders 23, and preferably terminates at the adjacent ends ofthe shoulders 23, or at least does not exceed in length the length ofthe space between them.

This arrangement of the shoulders 23 and 23a provides, in operatingeffect, an effective notch for the carrier frame engaging end of thespring 25. It has a distinct advantage in that the shoulders can bemolded integrally with the carrier frame. For example, the carrier framecan be formed by a pair of complementary dies movable to and from closedposition along a path normal to the plane of the carrier frame. Theshoulders 23 and 23a are formed by relatively simple die portions infixed position on the dies and are removed from shoulder formingposition simply by movement of the dies away from each other along thepath. Any other arrangement would require quite complicated die andexpensive die parts which would have to be movable relative to the frameforming dies on which they were carried.

The manner of mounting the bridging element 12 on the carrier frame 15,will be described. The carrier frame preferably is elongated endwise ofthe body and comprises side frame members 30 and end frame members 31and is supported by thesprings 25 with one face of the frame upwardlyand the end frame members 31 facing towards the ends of the body 1. Thebridging conductors 12 are connected to the end frame members 31 andsince the manner of attachment of each thereto is the same, theattachment of only one will be described in detail.

Referring to FIGS. 5 through 7, on each end frame member 31 is a ledge32 which has an upwardly open trough 33, the trough being defined by asupporting surface 34 on which one of the conductor elements 12 restsflatwise and which extends transversely of the length of the frame, asillustrated. The element 12 is constrained from displacement laterallyof the trough, endwise of the frame, by the side walls of the troughwhich provides suitable shoulders 35 and 36.

In order to hold the conductor element 12 in the trough, a suitablesnap-acting spring C-clarnp 37, having an upper arm 37a, a lower arm37b, and a base 370, is provided. This C-clamp is adapted to be receivedon the frame, and to be moved endwise of the frame and transversely ofthe trough, open end foremost, into operating position after theconductor 12 is disposed in the trough. In its operating position, itspans the upper open side of the trough and thus prevents displacementof the conductor 12 therefrom through the open side. A suitable socket38 is provided in the end frame member 31. This socket may be in theform of a small upright groove which has its open-side facing endwise ofthe frame toward the trough and which is open at its upper end,indicated at 39, at the top face of the frame. The ledge portion of theframe is provided at the outer end of the frame with an upright trough40 which has its open side facing outwardly endwise of the frame. Thetrough 40 is open at the top end, indicated at 41, and is open at thebottom end, indicated at 42 for engagement at the bottom end with theopen end of an inverted trough 43. The trough 4-3 is formed in the endframe member in spaced relation below the supporting surface 34 of thetrough 33. The inverted trough 43 extends in a direction transversely ofthe trough 33 and is adapted to receive endwise, and accommodate, thelower arm 37b of the C-clamp 37. Near the inner end of the trough 43 isa recess 44 which provides a shoulder over which a detent 45, formed onthe free end of the lower arm 37b of the C-clamp, snaps when the clampis installed and behind which the detent 45 seats to prevent accidentalwithdrawal of the C-clamp closed end foremost.

The upper surface of the outer portion of the frame which defines theshoulder 36 is preferably flush with the top of the conductor element 12when the conductor element 12 is seated in the trough 33. Thus, as theclamp 37 is pressed into operating position, open end foremost, theupper arm 37a slides across the top face of the frame member 31 andacross the top of the conductor element 12 until its free end seats inthe socket or trough 38. At the same time, the lower end 37b slidesalong the trough 43 until the detent 45 on its free end interengageswith the recess 44.

Thus, the clamp holds itself in operating position and prevents its ownaccidental withdrawal closed end foremost. Also, it holds the element 12in the trough 33. It is to be noted that the lower arm 37b and the base37c of the C-clamp 37 are deep seated in their notches and protected bythe notched side walls against accidental displacement. The C-clamp canbe readily removed for removal and replacement of the movable contactassembly, when desired.

Referring to FIGS. 8 through 11, the switch is shown with the carrierframe 15 and bridging conductor inverted relative to their positions asshown in FIG. 2. In this inverted position of the carrier, the bridgingconductor is inverted so that its contacts 13 become the lower contacts.The conductor can rock freely about the spring arm 37a for assuring goodengagement of its contacts with the stationary contacts. The pressureholding the bridging conductors with their contacts 13 against thestationary contacts 9 when the switch parts are at rest is applied bythe ledges 32 instead of by the spring arm 37a. In all other respects,the operation is the same.

Having thus described my invention, I claim:

1. A carrier for a movable contact and comprising an open frame having apair of spaced frame members, means on the frame adapted for connectinga conductor thereto for movement therewith in a path generally normal tothe plane of the frame, means on the frame for guiding the frame formovement in a direction normal to the plane of the frame, and means oneach of said frame members, at the inner faces thereof, for connectingthe end of a leaf spring thereto, said means comprising at least threeconnecting shoulders on each frame member, two of said shoulders beingarranged at the same side of a reference plane parallel to the plane ofthe frame, and the other shoulder being at the opposite side of thereference plane, said shoulders being totally out of alignment with eachother in a direction from one face of the frame to the other face, saidtwo shoulders being aligned with each other endwise of their associatedframe member and terminating in spaced relation to each other endwise oftheir assoiated frame member, and being disposed at opposite sides ofthe longitudinal mid-portion thereof, whereby a pas sage is providedbetween said two shoulders, said other shoulder being aligned with thepassage in a direction normal to the plane of the frame and said othershoulder terminating endwise of the associated frame member at locationswhich are at opposite sides of said longitudinal mid-portion and whichare nearer to said longitudinal midportion than said two shoulders,respectively, and said shoulders each having an operating face facinggenerally toward said reference plane.

2. A carrier for a movable contact of a switch and which is to beoperated with a snap action by a leaf spring, said carrier comprising aframe having elongated end frame members each with means for connectingthe spring thereto, said means on each member comprising at least onepair of shoulders adapted for engaging one face of a leaf spring at itsouter end to prevent its displacement of said end of the spring flatwiserelative to the frame toward one face of the frame and at least onecooperating shoulder adapted for engaging the other face of the leafspring at said outer end to prevent displacement of said outer end ofthe spring flatwise toward the other face of the frame, the shoulders ofsaid pair terminating, endwise of said associated frame member, inwardlyand transversely of the frame in spaced relation to the longitudinalmid-portion of the associated frame member, whereby a straight passagebetween the shoulders of said pair is provided, and said one cooperatingshoulder terminating endwise of the associated frame member so that itsends are nearer to the longitudinal mid-portion of the associated framemember than are the lateral limits of the passage.

3. In an electrical switch, a body, a pair of stationary contactscarried thereby, a movable conductor element having a pair of contactscomplementary to the stationary contacts, a carrier comprising a framehaving a pair of spaced end frame members, said frame supporting saidelement for movement to contact making and breaking relation uponmovement of the frame normal to its plane in opposite directions towardand away from the stationary contacts, an actuating member extendingthrough the frame, means supporting the actuating member for moveframe,dead center leaf spring means interposed between the frame and saidmember for moving the frame with a snap action in opposite directions,selectively, upon movement of the member in opposite directions,selectively, said dead center leaf spring means comprising a pair ofleaf springs normally arranged for flexure flatwise toward and away fromthe plane of the frame, one spring between each of said frame membersand the adjacent side of the actuating member, a plurality of connectingshoulder on each of said frame members connecting each leaf spring atits outer end to its associated frame member, means connecting each leafspring at its inner end to said adjacent side of the actuating member,for said flexure flatwise, each spring being normally flexed for urgingthe frame into contact making position, the point of connection of eachspring with the actuating member normally being spaced farther from theplane of the stationary contacts than its point of connection with theframe and its point of connection with the member being movable, bymovement of the actuating member in said one direction, to a positioncloser to the plane of the stationary contacts than its point ofconnection with the frame, whereby the point of connection with theactuating member passes dead center and the frame is moved away from thestationary contacts by the springs, said plurality of connectingshoulders on each frame member comprising at least one pair of shouldersengaging said outer end of the associated leaf spring and preventingdisplacement of said outer end flatwise in one direction from operatingpositions and a cooperating shoulder engaging said outer end of theassociated leaf spring and preventing displacement of said outer end inthe opposite direction from said operating positions, the shoulders ofsaid pair terminating, endwise of their associated frame member,inwardly of the frame in spaced relation to each other and at oppositesides of the longitudinal mid-portion of said associated end framemember, whereby a straight passage intersecting the plane of the frameand extending between the inner ends of said shoulders of said pair isprovided, and said cooperating shoulder terminating endwise of said endframe member so that the ends of the cooperating shoulders arepositioned endwise of their associated frame member nearer to themid-portion of their associated frame member than are the lateral limitsof said passage.

4. The structure according to claim 1 wherein all of said operatingfaces slope toward said reference plane in a direction toward thelongitudinal mid-portion of the frame.

5. The structure according to claim 1 wherein the frame is composed ofelectrical insulating material.

6. The structure according to claim ll wherein the operating faces ofsaid two shoulders are coplanar and the cooperating shoulder issubstantially equal in dimension, endwise of the associated framemember, to the distance between said two shoulders.

References Cited by the Examiner UNITED STATES PATENTS 1,709,656 4/29Clark 200-67 1,790,974 2/31 COX 20076 2,556,216 6/51 Raney 200-672,845,504 7/58 Iglehart 200--67 3,017,471 1/62 Karsh ZOO-76 BERNARD A.GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

2. A CARRIER FOR A MOVABLE CONTACT OF A SWITCH AND WHICH IS TO BEOPERATED WITH A SNAP ACTION BY A LEAF SPRING, SAID CARRIER COMPRISING AFRAME HAVING ELONGATED END FRAME MEMBERS EACHH WITH MEAN FOR CONNECTINGTHE SPRING THERETO, SAID MEANS ON EACH MEMBER COMPRISING AT LEAST ONEPAIR OF SHOULDERS ADAPTED FOR ENGAGING ONE FACE OF A LEAF SPRING AT ITSOUTER END TO PREVENT ITS DISPLACEMENT OF SAID END OF THE SPRING FLATWISERELATIVE TO THE FRAME TOWARD ONE FACE OF THE FRAME AND AT LEAST ONECOOPERATING SHOULDER ADAPTED FOR ENGAGING THE OTHER FACE OF THE LEAFSPRING AT SAID OUTER END TO PREVENT DISPLACEMENT OF SAID OUTER END OFTHE SPRING FLATWISE TOWARD THE OTHER FACE OF THE FRAME, THE SHOULDERS OFSAID PAIR TERMINATING, ENDWISE OF SAID ASSOCITED FRAME MEMBER, INWARDLYAND TRANSVERSELY OF HE FRAME IN SPACED RELATION TO THE LONGITUDINALMID-PORTION OF THE ASSOCIATED FRAME MEMBER, WHEREBY A STRAIGHTT PASSAGEBETWEEN THE SHOULDERS OF SAID PAIR IS PROVIDED, AND SAID ONE COOPERATINGSHOULDER TERMINATING ENDWISE OF THE ASSOCIATED FRAME MEMBER SO THAT ITSENDS ARE NEARER TO THE LONGITUDINAL MID-PORTION OFF THE ASSOCIATED FRAMEMEMBER THAN ARE THE LATERAL LIMITS OF THE PASSAGE.